Mushrooms have been used not only for food but also for medicine, and mushrooms with various medicinal benefits have been known. Among them, turkey tail mushroom is called “yun zhi” in Chinese medicine, and it allegedly has antitumor activity. In addition, an antitumor agent (common name: PSK, trade name: Krestin) that was developed from a protein polysaccharide derived from turkey tail mushroom has been clinically used.
In recent years, its selective binding to TGF-β and PDGF (patent literature 1), its preventive effect on cancer and infection by administering it to immune system immature animals (patent literature 2), and its inhibitory effect on preadipocyte differentiation (patent literature 3) have been reported.
However, the medicinal benefits of turkey tail mushroom have not completely been clarified. In addition, a strain with better effects, for the already-known effects, has been sought-after.
Patent Literature 1: Japanese Unexamined Patent Publication No. H08-113540
Patent Literature 2: Japanese Unexamined Patent Publication No. H11-60495
Patent Literature 3: Japanese Unexamined Patent Publication No. H2004-75640